The present invention relates to waveguides and more particularly to an arrangement to protect a waveguide section during transport and handling and also to support and protect a horizontal waveguide having a plurality of waveguide sections connected to each other in tandem suspended between two given spaced points.
For various practical reasons regarding roughness of terrain, personnel and vehicular traffic and required performance in communication, the transmission line in the form of a waveguide from the radio shelter to its remote antenna mast is usually suspended from a structural cable. This transmission line is very critical to the performance of the radio transmitter and receiver, particularly where the operating frequencies are in the fifteen gigahertz range. Such frequencies require a waveguide of small cross section making it quite vulnerable to damage. The buckling of its wall at any point in the run, because of excessive or accidental bending, can produce catastrophic results in communications. One method of reducing this vulnerablility to damage and buckling is to encase the waveguide for protection in handling and for limiting severe bending found in suspension, wind and ice loads.
The external cross sectional dimensions for the required copper waveguide are 0.475 inches.times.0.850 inches with a 0.050 inch wall. Since a practical length of this waveguide is 62 inches for each section, the slenderness ratio L/R of 165 makes it very susceptible to buckling when subjected to the bending moments developed in a long continuous run suspended from a cable. Obviously, relief through increased structural strength for the section is necessary to establish and increase reliability.